Explosion connector with ignition arrangement



Sept. 15, 1910 H. M. M DONALD 3.529.075

' EXPLOSION CONNECTOR WITH IGNITION ARRANGEMENT I Original Filed Nov. 13, 1967 if M1 72 I [d I f;- /6

United States Patent 3,529,075 EXPLOSION CONNECTOR WITH IGNITION ARRANGEMENT Harrison M. McDonald, De Kalb, Ill., assignor to Ideal Industries, Inc., Sycamore, 11]., a corporation of Delaware Continuation of application Ser. No. 682,191, Nov. 13, 1967. This application May 21, 1969, Ser. No. 830,197 Int. Cl. H02g 15/08 US. Cl. 174-87 14 Claims ABSTRACT OF THE DISCLOSURE This is a continuation of application Ser. No. 682,191, filed Nov. 13, 1967, and now abandoned.

SUMMARY OF THE INVENTION This invention is concerned with an explosive actuated connector for wires, cables and the like and more particularly with such a connector having self-contained ignition means.

An object of this invention is an explosive operated connector having a heat producing ignitor located in the bore of the connector.

Another object is a heat producing ignitor for such an explosive operated connector which may be actuated by the wires, cables and the like which are to be connected together.

Another object is a heat producing ignitor for an explosive connector which ignitor may be friction actuated.

Another object is an ignitor which renders an explosive connector safer to use.

Another object is an explosive operated connector having a heat sensitive explosive which is arranged to be more easily ignited by a heat producing source located in the bore of the connector.

Other objects may be found in the following specifications, claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal cross-sectional view through an explosive connector showing the ignitor and the wires to be connected positioned therein;

FIG. 2 is a plan view of a striker plate used with the ignitor of FIG. 1;

FIG. 3 is a modified form of the striker plate of FIG. 2;

FIG. 4 is yet another modification of the striker plate of FIG. 2;

FIG. 5 is a side elevational view partially in crosssection of the inner shell of the connector with a modified form of explosive formed thereon; and

FIG. 6 is a longitudinal cross-sectional view taken through the inner shell of the connector and showing yet another modified form of explosive.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an explosive operated connector of the type with which the ignitor of this invention may be utilized. Such a connector includes a deformable member 3,529,075 Patented Sept. 15, 1970 'ice such as a shell 11 having a bore 13 with an opening 15 at one end thereof and closed by a wall 16 at the opposite end thereof. Surrounding the deformable shell 11 is a nondeformable member also in the shape of a shell 17 having an opening 19 at one end thereof and a Wall 20 closing the opposite end thereof. The non-deformable shell 17 is spaced from at least a portion of the deformable shell 11 to form a chamber 21 therebetween. The open end of the shell 17 may be folded around the open end of the shell 11 at 22 to seal the chamber 21. Located in the chamber 21 is a heat sensitive explosive which is in the form of a thin sleeve 23 of nitrocellulose which fits tightly around the shell 11. The sleeve 23 may be molded, extruded or thermoformed. It may be sized to fit tightly on the shell 11 or it may be pressed on during assembly. An insulating plastic cap 25 is fitted over the non-deformable shell 17.

An ignitor device 31 is located in the bore 13 of the shell 11 in contact with a portion of the shell closely adjacent to the explosive 23. The ignitor is a three stage device including a heat producing tablet 33, a match 35 and a striking or ignition surface 37. Additionally, a striker plate 39 may be provided positioned in contact with the striking or ignition surface and located so that it may be engaged and rotated by the ends of the wires 41 or cables and the like which are inserted in the bore 13. The striker plate may be attached to the striking or ignition surface 37 by means of a small amount of adhesive which will break away as soon as the striker plate is rotated or by being placed on the striker surface while this surface is still wet. The striker plate may be retained in the bore without attachment to the striking surface by frictional contact with the inner wall of the shell 11.

The tablet 33 which is the final stage of the ignitor device and which provides suflicient heat upon burning to heat the shell 11 and ignite the explosive 23 is ring-shaped and may be made from a mixture of two moles zinc (200 mesh powder), one mole cuprous oxide (fine powder, reagent grade) and one-half mole antimony trioxide (Thermogard L., Metal and Thermit Co.). This tablet will weight about 150 mg.

The heat producing match 35 or second stage of the ignitor device is made from the material from which match heads are made, of the following formula:

Gm. Animal glue 8 K010 (60 mesh) 55 Silica (140 mesh) 24 Rosin (60 mesh) 5 ZnO (powder) 3 K Cr O7 0.25

1 In 20 gm. water.

The glue is soaked in the water for about an hour, the solution is heated to about F., the sifted and premixed dry ingredients are mixed in and the batch whipped to a density of about 1.0 to entrain air in the mixture. It has been found that the mixture burns better with this entrained air in it.

The striking surface 37 or first stage of the ignitor device is made of the material from which the tips of strike anywhere matches are made, of the following formula:

Gm. Animal glue 1 10 KClO (60 mesh) 10 Silica mesh) 35 Rosin (-60 mesh) 4 ZnO (powder) 6 P 5 (powder) 10 In 40 ml. water.

The glue is soaked in the water for about an hour, the solution is heated to about 110 F. and the sifted dry ingredients (except the P 8 are mixed in. When these ingredients are wetted, the P 8 is mixed in and the batch is whipped to a density of about 1.0 for use.

The match 35 is made by placing the tablet 33 at the bottom of a cavity .252 in diameter x .100" deep, and then troweling the previously mixed match material into the cavity. A small air vent at the bottom of the cavity allows the hole in the center of the tablet 33 to be filled. A small amount of the striking surface material is spread thinly on the top surface of the match material and the mold cavity is set aside in a current of unheated dry air to dry. When the finished ignitor is dry, it is pushed out of the cavity and is ready to be inserted into the connector. The match will weigh about 40-'60 mg., and the striking surface will weigh about 1-5 mg.

The tablet 33, match 35, and striking surface 37 may be made separately and fastened together mechanically or adhesively or they may be cast or pressed in three layers in a suitable mold or press. In addition, any of the components of the ignitor device 31 may have a different composition than those given here. For example, the tablet 33 may be made of combinations of aluminum and iron oxide, or zirconium and barium chromate or other metals and metal oxides. The match 35 may be pressed, instead of cast from a wet slurry, and may contain other oxidizers and fuels such as corn starch or cellulose and perchlorates or permanganates. The striking surface 37 may contain other friction sensitive materials such as calcium silicide.

While it may be satisfactory in some eases to ignite the striking or ignition surface 37 by engagement with the ends of the wires 41 it has been found desirable to provide a striker plate 39 to engage both the wires and the friction sensitive striking surface 37. One form of striker plate shown in FIGS. 1 and 2 has a number of sharp barbs 45 formed on one surface with the opposite surface covered with a frictional material 47 consisting of sand (about 40-60 mesh) cemented in place with lacquer. The striker plate is positioned in the bore 13 so that the barbs 45 will be contacted by the ends of the wires inserted in the bore and the frictional surface 47 will engage the striking surface 37 of the ignitor device 31. In the instances where the striker or ignition surface 37 is eliminated, the portion of the striking plate facing the ignitor device 31 is coated with red phosphorus bonded thereto by lacquer. This is essentially the material used on the striking strips of boxes and books of safety matches.

A modified form of striker-plate 51 is shown in FIG. 3. In this striker plate, the surface 53 which is to be engaged by the wires is faced with such materials as rubber, brake lining, plastic or cardboard or almost anything that the Wires can bite into to gain a mechanical grip to turn the striker plate. The opposite side of this striker plate which will engage the friction sensitive striking surface 37 may be faced with sand or abrasive material or with the safety match striker material containing phosphorus or calcium silicide.

FIG. 4 shows yet another modification of the striker plate. In this case the striker plate 55 has barbs 57 extending through both sides thereof to engage 'both the ends of the wires and the striking surface 37.

When the explosive is formed from a sheet of nitrated paper wrapped around the inner shell 11, the problem of supplying sufficient heat to ignite this nitrated paper becomes more critical than in the situation where the explosive is in the form of a tube of plastic tightly fitted to the shell. This is due to the fact that even a slight looseness in the wrapping of the nitrated paper around the shell interferes with heat transfer to the nitrated paper and necessitates the provision of more heat to bring about ignition of the nitrated paper. The heat transfer from the inner shell 11 to the nitrated paper 61 may also be improved by cementing the inner end of the strip of nitrated paper to the inner shell as shown at 63 in FIG. 5 so that the paper may be wrapped more tightly. While an inert cement may be used, it has been found to be more advantageous to use a cement made of a material such as nitrocellulose or double-base smokeless powder, both of which are igniti-ble from the heat passing through the shell 11. The outer end of the nitrated paper is secured to the paper by means of a drop of acetone (not shown) which melts or fuses the paper together. The use of a cement improves the heat transfer from the shell to the paper since heat transfer between solids is improved by filling the space between them with a substance which wets the surfaces of the solids and intimately contacts the solids.

An alternative means of forming the explosive by coating the outer surface of the inner shell 11 with a layer 65 of nitrocellulose is shown in FIG. 6. This may be done by dipping the inner shell 11 in a solution of nitrocellulose. The nitrocellulose coating formed on the inner shell is then dried and the inner shell is ready for assembly into a connector.

The use, operation and function of this invention are as follows:

The heat producing ignitor described above is intended to ignite a heat sensitive explosive located on the opposite side of a heat conductive wall in a connector. The ignitor is set off by manipulation of the wires, cables or the like which are inserted into the bore of the connector. The manipulation required to set olf the heat producing ignitor is merely rotation of the wires once they are positioned in the bore of the connector in contact with either the striking surface of the heat initiating ignitor or a striker plate positioned in contact with the striking surface. Of course, the wires, cables or the like may be maintained stationary and the connector rotated relative thereto.

The ignitor device is a three stage heat producing device. The first stage which comprises the striking or ignition surface 37 is highly sensitive to friction. Upon frictional engagement, the striking surface ignites, producing heat which ignites the second stage match 35 which is a combustible substance highly sensitive to heat. The ignition of the heat sensitive match 35 provides sufficient heat to ignite the third stage or tablet 33. Burning of the tablet 33 provides sufiicient heat to heat the deformable shell 11 and ignite the nitrocellulose explosive 23 which, upon burning, produces gases to crimp the shell 11 into contact with the wires 41 and the wires into contact with one another.

In addition to the ease and simplicity of operation provided by the ignitor device of this invention which is actuated by manipulation of the wires or the connector to be connected and requires no other ignition means, the ignitor also provides safety features in that by producing a large amount of heat inside the bore 13 of the connector, a user is discouraged from placing or keeping a finger inside the bore of the connector after ignition of the ignitor. Since there is a delay of several seconds from the time of actuation of the ignitor to the explosion of the heat sensitive explosive the user would be inclined to remove his finger from the bore before the deformable shell collapsed.

Whereas the ignitor device has been described as a three stage device, it should be understood that more or less stages may be used depending on the chemical substances used in the device and the means used for actuating the ignitor. Also, although it has been stated that the ignition device is actuated by frictional engagement with the wires either directly or with a striking plate it should be understood that other means may be utilized to actuate the ignitor device. For example, it may be desirable to use a pull-tab device to frictionally actuate the ignitor device. Also, it may be desirable in tact with said wire, cable or the like, the improvement comprising:

an easily ignitible heat producing substance positioned in said bore adjacent said explosive and capable of producing sufficient heat upon burning to bring about the ignition of said heat sensitive explosive.

2. The sturcture of claim 1 further characterized in that means to ignite said heat producing substance are positioned in said bore.

3. The structure of claim 2 further characterized in that said means to ignite said heat producing substance includes a heat producing friction sensitive substance.

4. The structure of claim 3 further characterized in that said heat producing friction sensitive substance is positioned to be engaged by a wire, cable or the like inserted in said bore so as to be actuated by twisting of said wire, cable or the like.

5. The structure of claim 2 further characterized in that said means to ignite said heat producing substance includes a heat sensitive ignitor material and a friction sensitive heat producing material.

6. The structure of claim 5 further characterized in that a striker plate is interposed between said friction sensitive heat producing material and the open end of the bore.

7. The structure of claim 1 further characterized in that said heat producing substance is positioned in contact with the portion of said deformable member located adjacent said explosive.

8. The structure of claim 1 further characterized in that said heat sensitive explosive is in the form of a paper thin elongated strip tightly wrapped around said deformable member with the inner end of said strip cemented to the deformable member to improve heat transfer to the explosive.

9. The structure of claim 1 further characterized in that said heat sensitive explosive is in the form of a coating applied to the deformable member.

10. A connector for attachment to at least one wire, cable or the like including:

a deformable member having a bore adapted to receive at least one wire, cable or the like,

at least one opening in said bore of suflicient size to receive at least one wire, cable or the like,

a non-deformable member enclosing and spaced from at least a portion of said deformable member to form a chamber therebetween,

a heat sensitive explosive located in said chamber and of sufficient quantity, when exploded, to deform said deformable member into physical contact with said wire, cable or the like, and

a heat producing device for igniting said explosive positioned in said bore adjacent said explosive, said heat producing device including:

a chemical adapted to produce heat upon ignition,

ignition means for said chemical including,

striking means positioned between said heat producing device and the opening into said bore so as to be operatively engaged by a wire, cable or the like inserted in said bore for actuation of said ignition means.

11. A connector including a deformable member having a bore adapted to receive at least one wire, cable or the like, at least one opening into said bore, a non-deformable member enclosing and spaced from at least a portion of said deformable member to form a chamber therebetween, and an explosive located in said chamber and of sufiicient quantity, when exploded, to deform said deformable member into crimping contact with said wire, cable or the like, the improvement comprising:

an ignitor located in said bore and adapted upon actuation to ignite said explosive.

12. The structure of claim 11 further characterized in that means to actuate said ignitor are positioned in said bore for engagement by a wire, cable or the like inserted in said bore,

said means being operable upon manipulation of said Wire, cable or the like.

13. The structure of claim 11 further characterized in that means to actuate said ignition are positioned in said how for engagement by a wire, cable or the like inserted in said bore,

said means being operable upon rotation of said wire,

cable or the like.

14. An electrical connector for making an electrical joint including a deformable shell having a central bore adapted to receive at least one wire, cable or the like, at least one opening into said bore, a non-deformable shell enclosing and spaced from at least a portion of said deformable shell to form a chamber therebetween, an explosive located in said chamber and of suflicient quantity, when exploded, to deform said deformable shell into crimping contact with the contents of the bore, and an ignitor in the connector responsive to manipulation of said one wire, cable or the like in the bore to ignite the explosive thereby deforming the deformable shell inwardly to provide a finished electrical connection.

References Cited UNITED STATES PATENTS 3,333,046 7/1967 Margis 17494 XR 3,341,650 9/1967 Broske 174-94 3,364,304 1/1968 Modrey 174-94 FOREIGN PATENTS 815,044 1/1959 Great Britain.

DARRELL L. CLAY, Primary Examiner US. Cl. X.R. 

